qemu/plugins/core.c
Stefan Hajnoczi ac90871cf8 lockable: add QemuRecMutex support
The polymorphic locking macros don't support QemuRecMutex yet.  Add it
so that lock guards can be used with QemuRecMutex.

Convert TCG plugins functions that benefit from these macros.  Manual
qemu_rec_mutex_lock/unlock() callers are left unmodified in cases where
clarity would not improve by switching to the macros.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-17 15:18:45 +01:00

503 lines
13 KiB
C

/*
* QEMU Plugin Core code
*
* This is the core code that deals with injecting instrumentation into the code
*
* Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
* Copyright (C) 2019, Linaro
*
* License: GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "qemu/config-file.h"
#include "qapi/error.h"
#include "qemu/lockable.h"
#include "qemu/option.h"
#include "qemu/rcu_queue.h"
#include "qemu/xxhash.h"
#include "qemu/rcu.h"
#include "hw/core/cpu.h"
#include "exec/cpu-common.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "exec/helper-proto.h"
#include "sysemu/sysemu.h"
#include "tcg/tcg.h"
#include "tcg/tcg-op.h"
#include "trace/mem-internal.h" /* mem_info macros */
#include "plugin.h"
struct qemu_plugin_cb {
struct qemu_plugin_ctx *ctx;
union qemu_plugin_cb_sig f;
void *udata;
QLIST_ENTRY(qemu_plugin_cb) entry;
};
struct qemu_plugin_state plugin;
struct qemu_plugin_ctx *plugin_id_to_ctx_locked(qemu_plugin_id_t id)
{
struct qemu_plugin_ctx *ctx;
qemu_plugin_id_t *id_p;
id_p = g_hash_table_lookup(plugin.id_ht, &id);
ctx = container_of(id_p, struct qemu_plugin_ctx, id);
if (ctx == NULL) {
error_report("plugin: invalid plugin id %" PRIu64, id);
abort();
}
return ctx;
}
static void plugin_cpu_update__async(CPUState *cpu, run_on_cpu_data data)
{
bitmap_copy(cpu->plugin_mask, &data.host_ulong, QEMU_PLUGIN_EV_MAX);
cpu_tb_jmp_cache_clear(cpu);
}
static void plugin_cpu_update__locked(gpointer k, gpointer v, gpointer udata)
{
CPUState *cpu = container_of(k, CPUState, cpu_index);
run_on_cpu_data mask = RUN_ON_CPU_HOST_ULONG(*plugin.mask);
if (cpu->created) {
async_run_on_cpu(cpu, plugin_cpu_update__async, mask);
} else {
plugin_cpu_update__async(cpu, mask);
}
}
void plugin_unregister_cb__locked(struct qemu_plugin_ctx *ctx,
enum qemu_plugin_event ev)
{
struct qemu_plugin_cb *cb = ctx->callbacks[ev];
if (cb == NULL) {
return;
}
QLIST_REMOVE_RCU(cb, entry);
g_free(cb);
ctx->callbacks[ev] = NULL;
if (QLIST_EMPTY_RCU(&plugin.cb_lists[ev])) {
clear_bit(ev, plugin.mask);
g_hash_table_foreach(plugin.cpu_ht, plugin_cpu_update__locked, NULL);
}
}
static void plugin_vcpu_cb__simple(CPUState *cpu, enum qemu_plugin_event ev)
{
struct qemu_plugin_cb *cb, *next;
switch (ev) {
case QEMU_PLUGIN_EV_VCPU_INIT:
case QEMU_PLUGIN_EV_VCPU_EXIT:
case QEMU_PLUGIN_EV_VCPU_IDLE:
case QEMU_PLUGIN_EV_VCPU_RESUME:
/* iterate safely; plugins might uninstall themselves at any time */
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_vcpu_simple_cb_t func = cb->f.vcpu_simple;
func(cb->ctx->id, cpu->cpu_index);
}
break;
default:
g_assert_not_reached();
}
}
static void plugin_cb__simple(enum qemu_plugin_event ev)
{
struct qemu_plugin_cb *cb, *next;
switch (ev) {
case QEMU_PLUGIN_EV_FLUSH:
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_simple_cb_t func = cb->f.simple;
func(cb->ctx->id);
}
break;
default:
g_assert_not_reached();
}
}
static void plugin_cb__udata(enum qemu_plugin_event ev)
{
struct qemu_plugin_cb *cb, *next;
switch (ev) {
case QEMU_PLUGIN_EV_ATEXIT:
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_udata_cb_t func = cb->f.udata;
func(cb->ctx->id, cb->udata);
}
break;
default:
g_assert_not_reached();
}
}
static void
do_plugin_register_cb(qemu_plugin_id_t id, enum qemu_plugin_event ev,
void *func, void *udata)
{
struct qemu_plugin_ctx *ctx;
QEMU_LOCK_GUARD(&plugin.lock);
ctx = plugin_id_to_ctx_locked(id);
/* if the plugin is on its way out, ignore this request */
if (unlikely(ctx->uninstalling)) {
return;
}
if (func) {
struct qemu_plugin_cb *cb = ctx->callbacks[ev];
if (cb) {
cb->f.generic = func;
cb->udata = udata;
} else {
cb = g_new(struct qemu_plugin_cb, 1);
cb->ctx = ctx;
cb->f.generic = func;
cb->udata = udata;
ctx->callbacks[ev] = cb;
QLIST_INSERT_HEAD_RCU(&plugin.cb_lists[ev], cb, entry);
if (!test_bit(ev, plugin.mask)) {
set_bit(ev, plugin.mask);
g_hash_table_foreach(plugin.cpu_ht, plugin_cpu_update__locked,
NULL);
}
}
} else {
plugin_unregister_cb__locked(ctx, ev);
}
}
void plugin_register_cb(qemu_plugin_id_t id, enum qemu_plugin_event ev,
void *func)
{
do_plugin_register_cb(id, ev, func, NULL);
}
void
plugin_register_cb_udata(qemu_plugin_id_t id, enum qemu_plugin_event ev,
void *func, void *udata)
{
do_plugin_register_cb(id, ev, func, udata);
}
void qemu_plugin_vcpu_init_hook(CPUState *cpu)
{
bool success;
qemu_rec_mutex_lock(&plugin.lock);
plugin_cpu_update__locked(&cpu->cpu_index, NULL, NULL);
success = g_hash_table_insert(plugin.cpu_ht, &cpu->cpu_index,
&cpu->cpu_index);
g_assert(success);
qemu_rec_mutex_unlock(&plugin.lock);
plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_INIT);
}
void qemu_plugin_vcpu_exit_hook(CPUState *cpu)
{
bool success;
plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_EXIT);
qemu_rec_mutex_lock(&plugin.lock);
success = g_hash_table_remove(plugin.cpu_ht, &cpu->cpu_index);
g_assert(success);
qemu_rec_mutex_unlock(&plugin.lock);
}
struct plugin_for_each_args {
struct qemu_plugin_ctx *ctx;
qemu_plugin_vcpu_simple_cb_t cb;
};
static void plugin_vcpu_for_each(gpointer k, gpointer v, gpointer udata)
{
struct plugin_for_each_args *args = udata;
int cpu_index = *(int *)k;
args->cb(args->ctx->id, cpu_index);
}
void qemu_plugin_vcpu_for_each(qemu_plugin_id_t id,
qemu_plugin_vcpu_simple_cb_t cb)
{
struct plugin_for_each_args args;
if (cb == NULL) {
return;
}
qemu_rec_mutex_lock(&plugin.lock);
args.ctx = plugin_id_to_ctx_locked(id);
args.cb = cb;
g_hash_table_foreach(plugin.cpu_ht, plugin_vcpu_for_each, &args);
qemu_rec_mutex_unlock(&plugin.lock);
}
/* Allocate and return a callback record */
static struct qemu_plugin_dyn_cb *plugin_get_dyn_cb(GArray **arr)
{
GArray *cbs = *arr;
if (!cbs) {
cbs = g_array_sized_new(false, false,
sizeof(struct qemu_plugin_dyn_cb), 1);
*arr = cbs;
}
g_array_set_size(cbs, cbs->len + 1);
return &g_array_index(cbs, struct qemu_plugin_dyn_cb, cbs->len - 1);
}
void plugin_register_inline_op(GArray **arr,
enum qemu_plugin_mem_rw rw,
enum qemu_plugin_op op, void *ptr,
uint64_t imm)
{
struct qemu_plugin_dyn_cb *dyn_cb;
dyn_cb = plugin_get_dyn_cb(arr);
dyn_cb->userp = ptr;
dyn_cb->type = PLUGIN_CB_INLINE;
dyn_cb->rw = rw;
dyn_cb->inline_insn.op = op;
dyn_cb->inline_insn.imm = imm;
}
static inline uint32_t cb_to_tcg_flags(enum qemu_plugin_cb_flags flags)
{
uint32_t ret;
switch (flags) {
case QEMU_PLUGIN_CB_RW_REGS:
ret = 0;
break;
case QEMU_PLUGIN_CB_R_REGS:
ret = TCG_CALL_NO_WG;
break;
case QEMU_PLUGIN_CB_NO_REGS:
default:
ret = TCG_CALL_NO_RWG;
}
return ret;
}
inline void
plugin_register_dyn_cb__udata(GArray **arr,
qemu_plugin_vcpu_udata_cb_t cb,
enum qemu_plugin_cb_flags flags, void *udata)
{
struct qemu_plugin_dyn_cb *dyn_cb = plugin_get_dyn_cb(arr);
dyn_cb->userp = udata;
dyn_cb->tcg_flags = cb_to_tcg_flags(flags);
dyn_cb->f.vcpu_udata = cb;
dyn_cb->type = PLUGIN_CB_REGULAR;
}
void plugin_register_vcpu_mem_cb(GArray **arr,
void *cb,
enum qemu_plugin_cb_flags flags,
enum qemu_plugin_mem_rw rw,
void *udata)
{
struct qemu_plugin_dyn_cb *dyn_cb;
dyn_cb = plugin_get_dyn_cb(arr);
dyn_cb->userp = udata;
dyn_cb->tcg_flags = cb_to_tcg_flags(flags);
dyn_cb->type = PLUGIN_CB_REGULAR;
dyn_cb->rw = rw;
dyn_cb->f.generic = cb;
}
void qemu_plugin_tb_trans_cb(CPUState *cpu, struct qemu_plugin_tb *tb)
{
struct qemu_plugin_cb *cb, *next;
enum qemu_plugin_event ev = QEMU_PLUGIN_EV_VCPU_TB_TRANS;
/* no plugin_mask check here; caller should have checked */
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_vcpu_tb_trans_cb_t func = cb->f.vcpu_tb_trans;
func(cb->ctx->id, tb);
}
}
void
qemu_plugin_vcpu_syscall(CPUState *cpu, int64_t num, uint64_t a1, uint64_t a2,
uint64_t a3, uint64_t a4, uint64_t a5,
uint64_t a6, uint64_t a7, uint64_t a8)
{
struct qemu_plugin_cb *cb, *next;
enum qemu_plugin_event ev = QEMU_PLUGIN_EV_VCPU_SYSCALL;
if (!test_bit(ev, cpu->plugin_mask)) {
return;
}
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_vcpu_syscall_cb_t func = cb->f.vcpu_syscall;
func(cb->ctx->id, cpu->cpu_index, num, a1, a2, a3, a4, a5, a6, a7, a8);
}
}
void qemu_plugin_vcpu_syscall_ret(CPUState *cpu, int64_t num, int64_t ret)
{
struct qemu_plugin_cb *cb, *next;
enum qemu_plugin_event ev = QEMU_PLUGIN_EV_VCPU_SYSCALL_RET;
if (!test_bit(ev, cpu->plugin_mask)) {
return;
}
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_vcpu_syscall_ret_cb_t func = cb->f.vcpu_syscall_ret;
func(cb->ctx->id, cpu->cpu_index, num, ret);
}
}
void qemu_plugin_vcpu_idle_cb(CPUState *cpu)
{
plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_IDLE);
}
void qemu_plugin_vcpu_resume_cb(CPUState *cpu)
{
plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_RESUME);
}
void qemu_plugin_register_vcpu_idle_cb(qemu_plugin_id_t id,
qemu_plugin_vcpu_simple_cb_t cb)
{
plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_IDLE, cb);
}
void qemu_plugin_register_vcpu_resume_cb(qemu_plugin_id_t id,
qemu_plugin_vcpu_simple_cb_t cb)
{
plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_RESUME, cb);
}
void qemu_plugin_register_flush_cb(qemu_plugin_id_t id,
qemu_plugin_simple_cb_t cb)
{
plugin_register_cb(id, QEMU_PLUGIN_EV_FLUSH, cb);
}
static bool free_dyn_cb_arr(void *p, uint32_t h, void *userp)
{
g_array_free((GArray *) p, true);
return true;
}
void qemu_plugin_flush_cb(void)
{
qht_iter_remove(&plugin.dyn_cb_arr_ht, free_dyn_cb_arr, NULL);
qht_reset(&plugin.dyn_cb_arr_ht);
plugin_cb__simple(QEMU_PLUGIN_EV_FLUSH);
}
void exec_inline_op(struct qemu_plugin_dyn_cb *cb)
{
uint64_t *val = cb->userp;
switch (cb->inline_insn.op) {
case QEMU_PLUGIN_INLINE_ADD_U64:
*val += cb->inline_insn.imm;
break;
default:
g_assert_not_reached();
}
}
void qemu_plugin_vcpu_mem_cb(CPUState *cpu, uint64_t vaddr, uint32_t info)
{
GArray *arr = cpu->plugin_mem_cbs;
size_t i;
if (arr == NULL) {
return;
}
for (i = 0; i < arr->len; i++) {
struct qemu_plugin_dyn_cb *cb =
&g_array_index(arr, struct qemu_plugin_dyn_cb, i);
int w = !!(info & TRACE_MEM_ST) + 1;
if (!(w & cb->rw)) {
break;
}
switch (cb->type) {
case PLUGIN_CB_REGULAR:
cb->f.vcpu_mem(cpu->cpu_index, info, vaddr, cb->userp);
break;
case PLUGIN_CB_INLINE:
exec_inline_op(cb);
break;
default:
g_assert_not_reached();
}
}
}
void qemu_plugin_atexit_cb(void)
{
plugin_cb__udata(QEMU_PLUGIN_EV_ATEXIT);
}
void qemu_plugin_register_atexit_cb(qemu_plugin_id_t id,
qemu_plugin_udata_cb_t cb,
void *udata)
{
plugin_register_cb_udata(id, QEMU_PLUGIN_EV_ATEXIT, cb, udata);
}
/*
* Call this function after longjmp'ing to the main loop. It's possible that the
* last instruction of a TB might have used helpers, and therefore the
* "disable" instruction will never execute because it ended up as dead code.
*/
void qemu_plugin_disable_mem_helpers(CPUState *cpu)
{
cpu->plugin_mem_cbs = NULL;
}
static bool plugin_dyn_cb_arr_cmp(const void *ap, const void *bp)
{
return ap == bp;
}
static void __attribute__((__constructor__)) plugin_init(void)
{
int i;
for (i = 0; i < QEMU_PLUGIN_EV_MAX; i++) {
QLIST_INIT(&plugin.cb_lists[i]);
}
qemu_rec_mutex_init(&plugin.lock);
plugin.id_ht = g_hash_table_new(g_int64_hash, g_int64_equal);
plugin.cpu_ht = g_hash_table_new(g_int_hash, g_int_equal);
QTAILQ_INIT(&plugin.ctxs);
qht_init(&plugin.dyn_cb_arr_ht, plugin_dyn_cb_arr_cmp, 16,
QHT_MODE_AUTO_RESIZE);
atexit(qemu_plugin_atexit_cb);
}